A DRAM device may need to perform a refresh operation periodically to maintain data stored therein. As understood by those skilled in the art, a memory controller, that is separate from the DRAM device, is sometimes used to control operation of the DRAM device (including the refresh operations) by issuing commands to the DRAM device. For example, the memory controller can issue a refresh command to the DRAM device so that the DRAM device performs a refresh operation. The DRAM device may be unable to perform other operations while performing a refresh operation.
The DRAM controller may be designed to periodically issue refresh commands in a set period of time. However, the DRAM controller may issue more refresh commands than required, thereby causing the DRAM device to perform unnecessary refresh operations, which may result in increased DRAM power consumption.